The blind and the sight impaired experience enhanced challenges in their day-to-day tribulations of every day life. One continuous challenge is that of navigating unfamiliar territory. The inability to fully comprehend near-field surroundings poses a threat to the safety of the sight impaired and can limit the sight impaired's ability to travel freely. To assist the sight impaired, the traditional ambulatory aid is the cane. The cane provides a two- to three-meter zone in front of the individual where large objects can be perceived through contact. The cane is a simple approach, and doubtless has been around since man has walked the Earth.
The cane is not the perfect solution, however. A cane is typically moved along the ground's surface as the individual walks, and thus can fail to detect obstacles which are not on the ground, such as those at head level. A cane cannot detect anything until the user maneuvers it in contact with an obstacle, which poses a problem since the user typically cannot see the obstacle, and thus the obstacle can evade detection. A cane provides no feedback as to the size or shape of the obstacle, or whether the obstacle is moving or dangerous. Relying on a cane, the individual must walk in a narrowly defined path behind the cane in order to remain as safe from peril as possible. In sum, while a cane is better than nothing, the absence of any meaningful feedback and the inherent dangers of moving in unfamiliar territory without a full near field comprehension make walking with a cane a dangerous proposition.
In some instances the cane has been replaced by the guide dog, an animal trained to lead the visually impaired. A guide dog is an expensive alternative, and has many of the drawbacks as the cane and includes a few additional drawbacks. Like the cane, a guide dog typically provides no feedback with respect to the obstacles in proximity to the user. A guide dog has a slightly broader range than the cane, but relegates the user to a passive stance rather than an active posture in determining obstacles. A guide dog is subject to illness and injury, and decision making is left to an animal, albeit a presumably well trained animal. Thus, there are inherent limitations and drawbacks associated with the use of a guide dog as well.